textproduct: Quad Cities

KEY MESSAGES

- There will be a period of 3-4 hours from mid-morning through early afternoon of winds gusting up to 40 mph ahead of the cold front.

- The Storm Prediction Center has a marginal (level 1 out of 5) risk of severe storms Monday afternoon/evening for the entire area. Damaging winds and hail are the primary risks.

- An omega block on the west coast will keep cooler than normal temperatures across the area Tuesday through Friday with another warm-up for the weekend.

SHORT TERM /THROUGH TONIGHT/

Issued at 158 AM CDT Sun May 3 2026

Upper level disturbance ahead of a cold front will sweep through the area through mid-day with isolated to scattered showers.

There has been a fairly persistent signal from the HRRR showing a period of 3-4 hours immediately behind the rain showers and ahead of the cold front of windy conditions. The latest iteration of the HRRR continues this signal but not as strong as previous runs. It does, however, appear there will be a period of wind gusts of up to 40 mph this morning west of the Mississippi. East of the Mississippi the wind gusts arrive late morning into early afternoon but only gusting up to 30-35 mph.

Right now there are no plans for any wind headlines. Observation trends through sunrise will be watched closely for any possible changes.

Early this evening winds will quickly drop to under 10 mph as high pressure quickly moves through the Midwest. Attention then turns to Monday.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 158 AM CDT Sun May 3 2026

Monday/Monday night Assessment...a certainty (>95%) of warmer than normal temperatures. Low to medium (25-50%) confidence on afternoon storms.

After a dry Monday morning, all models push a strong cold front through the area during the afternoon/evening. However, there are timing differences between the models. Additionally, although mid- level lapse rates will be quite steep, moisture availability is somewhat limited for storm development.

From the large scale, moisture has to work its way around high pressure over the Gulf. The longer trip with the moisture raises questions as to how much moisture will be available for diurnal convection.

The most likely scenario is for diurnal convection to develop right along the cold front during peak heating Monday afternoon. Given the timing differences with the cold front, the model consensus is indicating a more isolated (20%) coverage of convection for much of the area. The exception is the low end scattered (25-30%) coverage north of Highway 30.

Storm coverage may increase Monday evening as a weak low moves east northeast from Kansas into central Illinois. This is reflected in the 30-70% rain chances Monday evening from the model consensus with the highest pops from northeast Missouri toward Chicago. Interestingly, NBM 3 hr thunderstorm probabilities never get any higher than 25-30% Monday evening suggesting much lower coverage than the model consensus.

The deterministic ECMWF is even drier suggesting only 10-20% coverage Monday evening.

The Storm Prediction Center now has a marginal (level 1 out of 5) risk for severe storms Monday afternoon/evening. Again, moisture is limited but if storms do develop, the steep mid-level lapse rates would allow the stronger storms to produce 1 inch hail and 60 mph winds, especially with the stronger forcing from the approaching surface low.

Showers and some storms will persist late into Monday night as the weak low slowly moves through the area. The 'relatively' better rain chances will be south of I-80.

Tuesday through Saturday Assessment...very high (>85%) confidence of cooler than normal temperatures

Given the timing differences between the various models, the model consensus has rain persisting into Tuesday behind the front. The rain will slowly end from northwest to southeast during the afternoon with Tuesday night being dry.

The large omega block on the west coast will keep northwest flow and cool Canadian air across the Midwest for the remainder of the work week with a warm-up for the weekend. All models show weak disturbances in the flow aloft moving through the area on a near daily basis which would be capable of producing rain showers if sufficient moisture is present.

There are two disturbances of note that have the potential to bring diurnal showers; Thursday and Friday. A cold pocket of air aloft on Thursday will produce very steep mid-level lapse rates, which with daytime heating, should be more than enough to pop isolated to scattered (20-30%) showers Thursday afternoon. On Friday, the cold pocket aloft has moved off to the east so the mid-level lapse rates are not nearly as steep. Thus any diurnal showers would be more isolated at 10-20% coverage.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 615 AM CDT Sun May 3 2026

Isolated to scattered SHRA will end across eastern Iowa and most of northern Illinois by 18z/03. Observation trends across central Iowa show gusts 20-25 knots with isolated peak gusts of 30 knots. Thus earlier thinking of a 3-4 hour window behind the SHRA of gusts up to 35 knots still looks reasonable. Starting around 00z/04 wind speeds will drop to 10 knots or less as high pressure arrives. Guidance suggests winds will back and become southwest after 06z/04.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.